JP2008035421A - Communication device, relay device, communication system, communication method, and communication program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device having a plurality of interfaces for supporting a plurality of networks, which reduces power consumption by selecting an interface according to an electric wave receiving strength and contributes to maintaining reliability of communications. <P>SOLUTION: Communication devices (a communication terminal device 4 and a destination communication terminal device 5) which are connected to a plurality of networks by radio and communicate through each network are used. These communication devices comprise a plurality of interface parts supporting the networks (a cellular interface part CI and a WLAN interface part WI) and a control part (a power supply control part 38) which operates one of the interfaces by connecting to a power supply, connects an unused interface to a power supply according to the communication state of the interface in communication, and changes over the communication from the interface in communication to the unused interface. Thereby interface parts are changed over while maintaining communication with the communication destination. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention includes a plurality of interfaces such as an interface corresponding to a WLAN (Wireless Local Area Network) and an interface corresponding to a cellular network, and relates to communication control according to a communication state such as radio wave reception intensity, and particularly selects an interface. In addition, the present invention relates to a communication device, a relay device, a communication system, a communication method, and a communication program that perform a bypass call.

  For mobile communication such as cellular phones, there are standards such as cellular (cellular communication system) network, WLAN, etc., for example, CDMA (Code Division Multiple Access) -2000, W-CDMA (Wideband Code Division Multiple Access), There are GSM (Global System for Mobile Communications), etc., and WLAN includes, for example, IEEE (Institute of Electrical and Electronic Engineers) 802.11g, WiMAX (Worldwide Interoperability for Microwave Access) and the like. A line interface is required to support each network, and two line interfaces are required for a communication terminal device corresponding to both networks. Such a communication apparatus having two line interfaces has an advantage that communication can be performed by selecting a line interface.

Regarding mobile communication over a plurality of networks such as cellular networks and WLANs, Patent Document 1 can perform transmission / reception in a frequency band used in a wireless LAN and transmission / reception in a frequency band used in a mobile phone. In a communication apparatus constituting a multi-mode terminal, it is disclosed that the power supply of a signal processing unit is switched according to a reception state, and unnecessary power supply is stopped to realize low power consumption.
Japanese Patent Laying-Open No. 2005-73078 (summary, FIG. 1, FIG. 2, etc.)

  By the way, in a communication apparatus having a plurality of interfaces, energizing each interface causes wasteful power consumption, and a portable device driven by a battery greatly affects the life of the battery. Therefore, shutting off the power of the dormant interface suppresses power consumption and contributes to an increase in battery life in portable devices. Communication at the interface becomes impossible, and the degree of freedom of communication is hindered.

  The communication apparatus and the communication method described in Patent Document 1 continuously maintain power supply to one high-frequency unit, and put the power supply between the signal processing unit and the other high-frequency unit and signal processing unit in a reception state. Switching according to. For this reason, during communication, in the communication state using the other high-frequency unit, power is supplied to both high-frequency units, and there is a limit to reducing power consumption.

  In wireless communication, the radio wave reception strength affects the communication quality, and if the radio wave reception strength is insufficient, communication is impossible. In a communication apparatus having a plurality of interfaces corresponding to a plurality of networks such as a cellular network and a WLAN, it is possible to select a network according to the radio wave reception intensity. This is a merit that communication interruption due to decline can be avoided.

  It is desired to realize a highly convenient communication environment that does not impair the degree of freedom of communication, corresponding to the radio wave reception intensity and communication conditions of such an interface. For such a problem, Patent Document 1 does not have any disclosure or suggestion, nor does it disclose or suggest any means for solving the problem.

  Accordingly, an object of the present invention relates to a communication apparatus including a plurality of interfaces for supporting a plurality of networks, and selects an interface according to radio wave reception intensity, thereby reducing power consumption and contributing to maintaining communication reliability. There is to do.

Another object of the present invention relates to a communication apparatus including a plurality of interfaces for supporting a plurality of networks, and is to maintain communication by network switching corresponding to the selection of the interface.

  In order to achieve the above object, the present invention relates to a communication device that is wirelessly connected to a plurality of networks and performs communication through each network, and a plurality of interface units corresponding to the plurality of networks and a connection switching of the power supply, as well as corresponding thereto And a control unit for switching communication. If any one of these interface units is connected to a power source and operated, communication can be performed. During the communication, the communication state of the interface unit is monitored, and if the communication state deteriorates, the inactive interface unit is connected to the power source and the communication is switched from the in-communication interface unit to the other inactive interface unit. . If such switching of the interface unit is performed while maintaining communication, communication continuity and reliability are maintained. Further, by selectively connecting the interface unit to a power source, power saving such as battery consumption suppression can be achieved.

  Therefore, in order to achieve the above object, a first aspect of the present invention is a communication apparatus that is wirelessly connected to a plurality of networks and performs communication through each network, and a plurality of interface units corresponding to the networks, and these One of the interface units is connected to the power supply to operate, and depending on the communication state of the communicating interface unit, the suspended interface unit is connected to the power supply, and the other interface unit that has been suspended from the communicating interface unit And a control unit that switches communication, and the interface unit is switched while maintaining communication with the communication destination. With such a configuration, the above object can be achieved.

  In order to achieve the above object, a second aspect of the present invention is a relay device that is connected to a plurality of networks connected to a communication device and relays between each network, from a network in communication with the communication device. The call change request information is received and a control unit for changing the call is provided, and the call is changed to the network corresponding to the interface unit of the communication apparatus. The above object can also be achieved by such a configuration.

  In order to achieve the above object, a third aspect of the present invention is a communication system including a plurality of networks and a communication device that includes a plurality of interface units and is wirelessly connected to the network to perform communication. A configuration is provided that includes a switching processing unit that receives switching information of communication with the network accompanying switching of the interface unit from a communication device and switches a network that performs communication with the interface unit of the communication device. The above object can also be achieved by such a configuration.

  In order to achieve the above object, a fourth aspect of the present invention is a communication method that is wirelessly connected to a plurality of networks and performs communication through each network, and is operated by connecting a power source to any of the interface units. Monitoring the communication state of the communicating interface unit, connecting the inactive interface unit to a power source according to the communication state, operating the communication unit, and communicating with the other interface unit from the communicating interface unit. And switching the interface unit while maintaining communication with the communication destination. The above object can also be achieved by such a configuration.

To achieve the above object, according to a fifth aspect of the present invention, there is provided a communication program for causing a computer to perform communication, executing a process of connecting a power source to any of the interface units, A step of monitoring the communication state of the interface unit to determine deterioration of the communication state, a step of executing a process of connecting a power source to the inactive interface unit according to the communication state, and another interface from the communicating interface unit And a step of executing a process of switching communication to the unit. The above object can also be achieved by such a configuration.

  According to the present invention, the following effects can be obtained.

  (1) While maintaining communication, it is possible to save power by switching the connection of the power supply to the interface unit, and it is possible to maintain continuity and reliability of communication by switching the interface unit.

  (2) Since the network part can be selected by the interface part, it supports the selection conditions such as the radio wave reception strength and priority selection such as charging conditions, etc., and it contributes to the improvement of economics as well as the maintenance of communication reliability. it can.

  (3) The interface part can be automatically selected.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

[First Embodiment]

  A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a communication system to which the present invention is applied.

  As shown in FIG. 1, the communication system 2 includes, for example, a cellular network 6 or a wireless LAN (Wireless Local Area Network) as a plurality of communication lines (networks) using a communication terminal device 4 as a communication device. : WLAN) Network 8 or the like is used to configure a system capable of communication through the cellular network 6 or the WLAN network 8 and receive a radio wave while maintaining communication (call) with, for example, the partner communication terminal device 5 as a communication destination. The power supply connection between the cellular interface unit CI and the WLAN interface unit WI on the communication terminal device 4 side is switched according to communication conditions such as strength, and the communication range is expanded by selecting one of the networks 6 and 8. I am trying.

  In this case, the communication terminal device 4 and the counterpart communication terminal device 5 are provided with a cellular interface unit CI corresponding to the cellular network 6 and a WLAN interface unit WI corresponding to the WLAN network 8, which are communication units for each network. Configure. The cellular interface unit CI and the WLAN interface unit WI are set with identification information such as different telephone numbers in order to specify the line route.

  The cellular network 6 includes a cellular switch 10 as a server device for the communication terminal device 4 and the counterpart communication terminal device 5 and a plurality of base stations 121, 122..., And the WLAN network 8 includes the communication terminal device 4 In addition, a SIP server 14 and a plurality of WLAN access points (WLAN-AP) 161, 162,... The communication terminal device 4 is connected to the cellular switch 10 via the base station 121 by the cellular radio wave 18 and is also connected to the WLAN-AP 161 as a relay station through the WLAN radio wave 19. Similarly, the partner communication terminal device 5 is also connected to the cellular exchange 10 via the base station 122 by the cellular radio wave 18 and is also connected to the WLAN-AP 162 as a relay station via the WLAN radio wave 19. A call between the communication terminal device 4 and the partner communication terminal device 5 is established by such connection relationships.

  A gateway 20 is connected between the cellular network 6 and the WLAN network 8 as a relay device for switching a call with the communication terminal device 4. The cellular network 6 and the WLAN network 8 communicate with each other via the gateway 20. Is done.

  A communication method used in such a communication system 2 will be described with reference to FIGS. FIG. 2 is a flowchart showing a processing procedure on the communication terminal apparatus 4 side, and FIG. 3 is a flowchart showing a processing procedure on the network side.

  In the communication terminal device 4, as shown in FIG. 2, either the cellular interface unit CI or the WLAN interface unit WI is selected (step S1), and a call is set up. The selection of the cellular interface unit CI or the WLAN interface unit WI is executed by connecting a power source to one of them. Here, a call is an event in which a user uses a communication line for the purpose of communication, and is a state where the user is connected to the line from the occurrence thereof and occupies the line until the communication ends.

  In either case of the cellular interface unit CI or the WLAN interface unit WI, the communication state such as the radio wave reception intensity is monitored in the communication state (step S2). The monitoring of the communication state is performed by comparing the radio wave reception intensity received through the cellular interface unit CI or the WLAN interface unit WI with, for example, a reference value. What is necessary is just to determine with a favorable communication state. Therefore, for example, when the communication state deteriorates during communication with the WLAN interface unit WI, a power source is connected to the suspended cellular interface unit CI to check the radio wave reception intensity and the like. If communication is possible, the cellular interface unit CI is changed (step S3), the cellular interface unit CI takes over communication, and the network side is requested to change the call (step S4). A call change is a call transfer from the cellular interface unit CI to the WLAN interface unit WI, or a call transfer from the WLAN interface unit WI to the cellular interface unit CI. To take over. Such processing is continuously performed until communication is completed. This communication method is realized, for example, by executing a communication program described later.

  On the network side, as shown in FIG. 3, a call change request is received during communication with the communication terminal device 4 (step S11), and the call change is executed based on the request (step S12). Maintain communication. Call modification is performed through the gateway 20 by the cellular network 6 and the WLAN network 8. Such processing is continued as long as communication is maintained. This communication method is realized, for example, by executing a communication program described later.

  Next, the communication terminal device 4 will be described with reference to FIGS. 4, 5, and 6. 4 is a diagram illustrating an example of a communication terminal device, FIG. 5 is a diagram illustrating a configuration example of a program / data storage memory, and FIG. 6 is a diagram illustrating an example of a communication terminal device. 4 and 6, the same parts as those in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 4, the communication terminal apparatus 4 includes a cellular interface unit CI and a WLAN interface unit WI. The cellular interface unit CI is a functional unit for supporting the base station 121 connected to the cellular switch 10. It includes an antenna 22, a cellular RF (Radio Frequency) front end portion 24, and a cellular baseband portion 26. The WLAN interface unit WI is a functional unit for supporting the WLAN-AP 161 on the SIP server 14 side, and includes an antenna 28, a WLAN-RF front end unit 30, and a WLAN baseband unit 32. The radio waves received by the cellular interface unit CI and the WLAN interface unit WI are used for monitoring the radio wave reception intensity for switching the connection between the cellular interface unit CI or the WLAN interface unit WI and the power source, separately from communication.

  Each of the cellular interface unit CI and the WLAN interface unit WI is configured to operate independently. Each interface unit CI and WI includes a power supply line 34 and 36 provided individually, and a common power control unit 38. The battery 40 is connected through the power supply unit 38 and the power supply from the battery 40 is controlled by the power control unit 38. Specifically, the power supply control unit 38 has a power feeding switching function, and power feeding between the cellular interface unit CI and the WLAN interface unit WI is selected as necessary. The cellular interface unit CI, the WLAN interface unit WI, and the power supply control unit 38 are executed by control means mounted on the communication terminal device 4, that is, a communication control program 62 (FIG. 5) by a computer or the like.

  The interface units CI, WI, and power supply control unit 38 include a CPU (Central Processing Unit) 42 that constitutes a control unit or an information processing unit for monitoring radio wave reception intensity, feeding control, communication control, and other controls. The program / data storage memory 46, the work memory 48, the input unit 50, the display unit 52, and the audio control unit 54 are connected to the CPU 42 through the control line 44 and the data bus 56. The program / data storage memory 46 includes a recording medium such as a ROM (Read-Only Memory). The program / data storage memory 46 is a recording medium for storing programs and data executed by such a computer. For example, as shown in FIG. 5, a program storage area 58 and a data storage area 60 are set, The storage area 58 stores programs such as the communication control program 62, and the data storage area 60 stores various data. The work memory 48 is composed of a RAM (Random-Access Memory) and is used as a work area.

  The input unit 50 is controlled by the CPU 42 and is a means for inputting various information to the CPU 42. Under the control of the CPU 42, the display unit 52 displays various information such as a communication destination, selected interface unit CI, WI selection information, mail information, and the like. The voice control unit 54 transmits and receives a call voice based on the control of the CPU 42. Therefore, the voice control unit 54 is connected to a speaker 64 that reproduces the received signal as voice and outputs it, and a microphone 66 that inputs the transmitted voice and converts it into an electrical signal.

  For example, as shown in FIG. 6, the communication terminal device 4 is configured such that casings 67 and 69 can be folded by a hinge part 71, and the input part 50 including cursor keys and character keys is provided in the casing 67. The housing unit 69 includes antennas 22 and 28, for example, a display unit 52 composed of an LCD (Liquid Crystal Display), a speaker 64, and the like. The display unit 52 displays a power connection state of the cellular interface unit CI or the WLAN interface unit WI during a call start or during a call. When switching these power connections by manual operation, the dialog display and the contents of setting instructions are displayed on the display unit 52.

  In such a communication terminal device 4, at the start of communication (call), either the cellular interface unit CI or the WLAN interface unit WI is connected to a power source, and communication is started. During communication, the level of radio wave reception intensity is monitored as a communication status monitor. If the communication state deteriorates in the WLAN interface unit WI during communication, the other cellular interface unit CI is connected to the power supply while the communication is maintained, and the radio wave reception intensity is detected. As a result, when it is determined that the communication state at the other cellular interface unit CI is good, the communication is switched to the communication at the cellular interface unit CI, and the switching of the communication, that is, the call change is requested to the network side. As a result, the connection is switched from the WLAN network 8 to the cellular network 6 in response to the operation switching from the WLAN interface unit WI to the cellular interface unit CI by switching the connection of the power source, and the communication is continued.

  In this case, the communication state on the cellular interface unit CI side is monitored, and if the communication state on the cellular interface unit CI side deteriorates, the communication is switched again to the WLAN interface unit WI and the WLAN network 8 to communicate with the call destination. To continue.

  Next, a cellular exchange will be described with reference to FIGS. FIG. 7 is a diagram showing an example of a cellular exchange, and FIG. 8 is a diagram showing a configuration example of a program / data storage memory. In FIG. 7, the same parts as those in FIG.

  As shown in FIG. 7, the cellular switch 10 includes base stations 121, 122,... 12N corresponding to a plurality of communication terminals and subscriber line interface units 681, 682, 683,. 68N is provided, and these subscriber line interface units 681, 682, 683... 68N are connected to the exchange switch unit 70, and a line interface unit 72 is connected to the exchange switch unit 70. The exchange switch unit 70 selects the line interface unit 72 according to the incoming call, and establishes connection between the communication destinations. The line interface unit 72 receives an incoming call signal from the line and transmits it to the exchange switch unit 70.

  These subscriber line interface units 681, 682, 683... 68N, the exchange switch unit 70, and the line interface unit 72 are connected to the CPU 76, the program / data storage memory 78, and the work memory 80 through the control line 74 to constitute a computer. The CPU 76, the program / data storage memory 78, and the work memory 80 are connected by a data bus 82. The CPU 76 is a control unit and an information processing unit, and executes a program stored in the program / data storage memory 78. The subscriber line interface units 681, 682, 683... 68N, the exchange switch unit 70 and the line Controls the interface unit 72, receives incoming call processing, receives a switching instruction notification from the communication terminal device 4, stores the notification content in the program / data storage memory 78, and executes communication control such as execution of the switching instruction notification content when the incoming call is received. Execute. The program / data storage memory 78 is a recording medium for storing programs and data executed by a computer, and includes a program storage area 84 and a data storage area 86 as shown in FIG. A communication control program corresponding to the communication control program 62 is stored. The work memory 80 is composed of a RAM and is used for a work area.

  Next, the SIP server will be described with reference to FIGS. FIG. 9 is a diagram illustrating an example of a SIP server, and FIG. 10 is a diagram illustrating a configuration example of a program / data storage memory. 9, the same parts as those in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 9, the SIP server 14 includes a network interface unit 88 connected to the WLAN network 8. The network interface unit 88 includes a CPU 90 that constitutes a computer as a control unit or an information processing unit, A program / data storage memory 92 and a work memory 94 are connected by a control line 96 and a data bus 98. The program / data storage memory 92 is a recording medium for storing programs and data executed by a computer, and includes a program storage area 100 and a data storage area 102 as shown in FIG. A communication control program corresponding to the communication control program 62 is stored. The work memory 94 is composed of a RAM and is used for a work area.

  Next, the gateway will be described with reference to FIG. 11 and FIG. FIG. 11 is a diagram illustrating an example of a gateway, and FIG. 12 is a diagram illustrating a configuration example of a program / data storage memory. In FIG. 11, the same parts as those in FIG.

  The gateway 20 is a relay point of a network or a device that performs a relay function. As shown in FIG. 11, the gateway 20 is an exchange interface unit 104, a network interface unit 106, a control unit or an information processing unit, a CPU 108, a program / data storage memory. 110 and a working memory 112 are connected by a control line 114 and a data bus 116. The cellular network 6 is connected to the exchange interface unit 104, and the WLAN network 8 is connected to the network interface unit 106. Therefore, the cellular network 6 and the WLAN network 8 are connected via a gateway 20.

  The program / data storage memory 110 is a recording medium for storing programs and data executed by a computer, and includes a program storage area 118 and a data storage area 120 as shown in FIG. A communication control program corresponding to the communication control program 62 is stored. The work memory 112 is composed of a RAM and is used for a work area.

  Next, the processing procedure of the communication terminal device 4 will be described with reference to FIG. FIG. 13 is a flowchart showing the processing procedure of the communication program of the communication terminal device 4.

  This processing procedure is a processing of a communication program in the communication terminal device 4 for realizing the above-described communication method, switching the interface unit during communication, and switching the power source for each interface unit in units of the interface unit. ing. In other words, the front end unit and the baseband unit are connected to the power supply in a lump, or the connection is released.

  In this processing procedure, at the start of communication, a power source is connected to the WLAN interface unit WI and communication is started (step S21). During communication by the WLAN interface unit WI, the radio wave reception intensity is measured, and it is determined whether the measured value is equal to or greater than a specified value (step S22). If the measured value is greater than or equal to the specified value, communication at the WLAN interface unit WI is maintained. If the measured value is less than the specified value, a power source is connected to the cellular interface unit CI, and the radio waves on the cellular interface unit CI side The received intensity is measured, and it is determined whether the measured value is greater than or less than a specified value (step S23). If the measured value is less than the specified value, communication with the cellular interface unit CI is impossible, and the power is cut off from the cellular interface unit CI (step S24). When the communication is completed, the communication disconnection process is executed (step S25), the power to the WLAN interface unit WI is disconnected (step S26), and the communication is terminated.

  In step S23, if the measured value of the radio wave reception intensity of the cellular interface unit CI is equal to or greater than the specified value, communication at the cellular interface unit CI is possible, so the cellular network 6 side (cellular switch 10) and the WLAN network 8 side. (SIP server 14) is requested to respond to connection switching (step S27), a connection (call) is set in the cellular interface unit CI, and communication is taken over from the WLAN interface unit WI to the cellular interface unit CI (step S28). Continue communication. After this setting, the power supply to the WLAN interface unit WI is turned off (step S29).

  During communication with the cellular interface unit CI, a power source is periodically connected to the WLAN interface unit WI, the radio wave reception intensity on the WLAN interface unit WI side is measured, and whether the measured value is greater than or less than a specified value. Determination is made (step S30). If the measured value is less than the specified value, the communication at the cellular interface unit CI is maintained. If the measured value is equal to or greater than the specified value, the cellular network 6 side (cellular switch 10) and the WLAN network 8 side ( The SIP server 14) is requested to cope with connection switching (step S31), a connection (call) is set in the WLAN interface unit WI, and communication is continued (communication is taken over from the cellular interface unit CI to the WLAN interface unit WI). (Step S32). After this setting, the power is disconnected from the cellular interface unit CI (step S33).

  Next, the processing procedure of the SIP server 14 will be described with reference to FIG. FIG. 14 is a flowchart showing the processing procedure of the communication program of the SIP server 14.

  This processing procedure is an execution process of a communication program for realizing a communication method on the SIP server 14 side corresponding to a connection request using the WLAN interface unit WI of the communication terminal device 4. Either the WLAN interface unit WI or the cellular interface unit CI may be used for the start of communication. In this case, the communication is started by using the WLAN interface unit WI preferentially. B and call C are established sequentially. Here, the call A is a connection between the WLAN interface unit WI of the communication terminal device 4 and the WLAN interface unit WI of the counterpart communication terminal device 5, and the call B is a cellular interface unit CI of the communication terminal device 4 and the counterpart communication terminal device 5. The connection to the WLAN interface unit WI, call C, is established by a change from the call B, and is a connection between the WLAN interface unit WI of the communication terminal device 4 and the WLAN interface unit WI of the counterpart communication terminal device 5. That is, the call A is a call that is set first as a call state. In this case, the call A is a call made by the communication terminal device 4 and the partner communication terminal device 5 both using the WLAN interface unit WI. Call. Since the communication state of the WLAN interface unit WI of the communication terminal device 4 deteriorated during the call of the call A, the call with the communication terminal device 4 switched to the cellular interface unit CI is a call B. Since the communication state of the cellular interface unit CI of the communication terminal device 4 has deteriorated, the call using the WLAN interface unit WI in the communication terminal device 4 is referred to as call C again. In this case, the call C is in a state of being restored from the cellular interface unit CI to the WLAN interface unit WI in order to establish the condition that the WLAN interface unit WI has priority. That is, when three or more interface units are used, this means that the priority interface unit is restored.

  Therefore, the SIP server 14 receives a connection request from the communication terminal device 4 (step S41). Upon receiving this connection request, the SIP server 14 requests connection of the call A (call A in FIG. 18) to the partner communication terminal device 5 that is the communication destination (step S42). When receiving the acceptance of connection acceptance from the partner communication terminal device 5, the communication terminal device 4 is notified of the acceptance (step S43).

  As a result, direct communication between the communication terminal device 4 and the partner communication terminal device 5 is started (step S44). When a call change request is received from the communication terminal device 4 during the call (step S45), the gateway 20 is requested to connect the call B (call B in FIG. 19) (step S46).

  Upon receiving the acceptance of connection acceptance from the gateway 20 (step S47) and receiving the acceptance of connection acceptance of the call B from the counterpart communication terminal device 5 (step S48), the SIP server 14 calls the gateway 20 and the counterpart communication terminal device 5 Recognize that B can be set. Therefore, the communication terminal device 4 is notified of the approval of the call change (step S49). The partner communication terminal device 5 establishes a direct call with the gateway 20 and establishes a call with the communication terminal device 4 via the gateway 20 (step S50).

  Further, when a request for change to call C (call C in FIG. 20) is received from communication terminal device 4 (step S51), request is made to counterpart communication terminal device 5 for change to call C (step S52). The call change is determined (step S53).

  In step S53, when an acceptance of the change acceptance is received from the counterpart communication terminal device 5, an acknowledgment of the change to the call C is sent to the communication terminal device 4 (step S54). Further, when a call B disconnection request is received from the gateway 20, the partner communication terminal apparatus 5 is requested to disconnect the call B (step S55), and when a disconnection approval is received from the partner communication terminal apparatus 5 (step S55). In step S56, an acknowledgment of disconnection is sent to the gateway 20 (step S57).

  According to such a processing procedure, call setting and call disconnection processing in the SIP server 14 is performed while maintaining communication.

  Next, the processing procedure of the gateway 20 will be described with reference to FIG. FIG. 15 is a flowchart showing the processing procedure of the communication program of the gateway 20.

  The processing procedure of the gateway 20 corresponds to the processing of the communication program for realizing the communication method of the communication terminal device 4 and the SIP server 14, and receives an incoming call from the communication terminal device 4 via the cellular network 6. This is a case of executing processing.

  When there is an incoming call from the communication terminal device 4 via the cellular network 6 (step S61), a call with the communication terminal device 4 is set (step S62). Also, a call B connection request is received from the SIP server 14 (step S63), and the SIP server 14 is notified of the acceptance of the connection, and waits for call setting from the partner communication terminal device 5 (step S64).

  If a connection request is received from the partner communication terminal device 5 (step S65), a call with the communication terminal device 4 is established via the cellular exchange 10 (step S66). If a call B disconnection request is received from the cellular exchange 10 (step S67), the SIP server 14 is requested to disconnect the call B (step S68). The disconnection is received from the corresponding SIP server 14 (step S69), the call with the cellular exchange 10 is disconnected (step S70), and the process is completed.

  According to such processing procedure, call setting and call disconnection processing in the gateway 20 is performed while maintaining communication.

  Next, the processing procedure of the cellular exchange 10 will be described with reference to FIG. FIG. 16 is a flowchart showing the processing procedure of the communication program of the cellular exchange 10. This processing procedure is a communication program execution process for realizing the communication method.

  The cellular exchange 10 receives a request for call setting or call disconnection associated with switching between the WLAN interface unit WI and the cellular interface unit CI from the communication terminal device 4 in communication, and performs processing corresponding thereto.

  Therefore, a request for switching of communication is generated from the communication terminal device 4 with switching of the cellular interface unit CI and the WLAN interface unit WI of the communication terminal device 4. The cellular exchange 10 receives such a request from the communication terminal device 4 (step S71) and determines the content of the request (step S72). If the requested content is a call setting request, the call is set in the communication terminal device 4 and the gateway 20 (step S73). If the requested content is call disconnection, a request for call disconnection is made to the gateway 20 (step S74).

  When the call disconnection request is received and the call disconnection is received from the gateway 20 (step S75), the call B with the communication terminal device 4 is disconnected (step S76), and the process is terminated.

  By such processing procedures, call setting and call disconnection processing from the cellular exchange 10 is performed in conjunction with the communication terminal device 4.

  Next, processing procedures of the communication terminal device 4, the network, and the partner communication terminal device 5 will be described with reference to FIGS. 17 to 20 are sequence diagrams showing processing procedures of the communication program in the communication terminal device 4, the network and the partner communication terminal device 5. FIG. 21 is a diagram showing communication between the communication terminal devices using only the SIP server. These are figures which show the communication between the communication terminal devices which intervened the SIP server, the gateway, and the cellular switchboard. 17, 18, 19, and 20, call A, call B, and call C correspond to call A, call B, and call C in FIGS. 14, 15, and 16, respectively.

  This processing sequence shows a sequence of processing that is executed between the communication terminal device 4 and the counterpart communication terminal device 5 with the network side cellular switching device 10, the SIP server 14, and the gateway 20 interposed therebetween. The process which considered the change of is performed.

  Therefore, in this processing sequence, as shown in FIG. 17, the basic call setting process (step S100) (FIG. 18), the radio wave reception intensity of the WLAN interface unit WI becomes weak, and the cellular interface unit CI is used. The call change process (step S200) (FIG. 19), the radio wave reception intensity of the cellular interface unit CI is weak (or the radio wave reception intensity of the WLAN interface unit WI is strong under the condition that the WLAN interface unit WI has priority). Case) Call change processing (step S300) (FIG. 20) in the case of using the WLAN interface unit WI is included.

  The call change process (step S200) includes a call setting on the cellular network 6 side (step S210) and a call setting on the WLAN network 8 side (call change) (step S220). Step S300 includes confirmation of call setup on the WLAN network 8 side (step S310) and disconnection on the cellular network 6 side (step S320).

  In the basic call setting process (step S100), as shown in FIG. 18, a request for setting a call A is issued from the WLAN interface unit WI to the SIP server 14 (step S101). A call A setting request is issued to the WLAN interface unit WI of the terminal device 5 (step S102). A connection acceptance acknowledgment is issued from the WLAN interface unit WI of the counterpart communication terminal device 5 to the SIP server 14 (step S103), and a notification of the connection acceptance acknowledgment is issued from the SIP server 14 to the WLAN interface unit WI of the communication terminal device 4. (Step S104). Through these processes, a call (call A) is started between the WLAN interface unit WI of the communication terminal device 4 and the WLAN interface unit WI of the counterpart communication terminal device 5 (step S105).

  In the call setting process (step S210) on the cellular network 6 side, as shown in FIG. 19, a call setting request is issued from the cellular interface unit CI to the cellular switch 10 (step S211), and the cellular interface unit CI and the gateway 20 are connected. Is set up by the cellular exchange 10 (step S212).

  In call setting (call change) on the WLAN network 8 side (step S220), a call change request is issued from the WLAN interface unit WI to the SIP server 14 (step S221), and the SIP server 14 sets the call B to the gateway 20. A request is issued (step S222), the gateway 20 issues a connection acceptance acknowledgment to the SIP server 14 (step S223), and the SIP server 14 sends a call B setting request to the WLAN interface unit WI of the counterpart communication terminal device 5. Is issued (step S224), and a notification of connection acceptance is sent from the WLAN interface unit WI to the SIP server 14 (step S225). In response, the SIP server 14 notifies the WLAN interface unit WI of the communication terminal device 4 of the call change approval (step S226), and the WLAN interface unit WI of the partner communication terminal device 5 transmits the WLAN interface unit WI of the communication terminal device 4 to the WLAN interface unit WI. On the other hand, the call A is disconnected (step S227). As a result, in response to the call setting (step S212) by the cellular exchange 10, a call connection is made to the gateway 20 with the WLAN interface unit WI of the counterpart communication terminal device 5 (step S228), and the counterpart communication terminal device. A call connection completion notification is issued from the WLAN interface unit WI of 5 to the WLAN interface unit WI of the communication terminal device 4 (step S229). Thereby, the call B is started as a call on the new route (step S230).

  In the call setting possibility confirmation process on the WLAN network 8 side (step S310), as shown in FIG. 20, a request for change from call B to call C is made from the WLAN interface unit WI of the communication terminal apparatus 4 to the SIP server 14. The SIP server 14 issues a request to change the call B to the call C to the WLAN interface unit WI of the partner communication terminal device 5 (step S312). When a change acceptance acceptance is issued from the WLAN interface unit WI of the partner communication terminal device 5 to the SIP server 14 (step S313), a notification of the acceptance of change acceptance is issued from the SIP server 14 to the WLAN interface unit WI (step S313). S314).

  In the disconnection process (step S320) on the cellular network 6 side, the cellular interface unit CI issues a request to disconnect the call B to the cellular exchange 10 (step S321), and the cellular exchange 10 disconnects the call to the gateway 20. A request is issued (step S322), and a call disconnection request is issued from the gateway 20 to the SIP server 14 (step S323). As a result, the SIP server 14 disconnects the call B to the WLAN interface unit WI of the partner communication terminal device 5. The request is notified (step S324).

  When the partner communication terminal device 5 that has received this disconnection request disconnects the call, the WLAN interface unit WI issues a disconnection acknowledgment to the SIP server 14 (step S325), and the SIP server 14 acknowledges the disconnection to the gateway 20. Is issued (step S326), the gateway 20 performs a disconnection process on the cellular exchange 10 (step S327), and the cellular exchange 10 performs a disconnection process on the cellular interface unit CI (step S328).

  Through such processing, the partner communication terminal device 5 starts the call C immediately after issuing the disconnection acknowledgment of the call B (step S329), and the WLAN interface unit WI of the communication terminal device 4 and the WLAN interface of the partner communication terminal device 5 Communication with call unit WI is established by call C.

  By such processing, basic call setting is performed between the WLAN interface unit WI of the communication terminal device 4 and the partner communication terminal device 5 through the SIP server 14 of the WLAN network 8 as shown in FIG. Since the radio wave reception intensity on the WLAN interface unit WI side is lowered, the call is changed. In this case, as shown in FIG. 22, the WLAN interface unit of the counterpart communication terminal device 5 from the cellular interface unit CI of the communication terminal device 4 via the cellular switch 10 of the cellular network 6, the gateway 20, and the SIP server 14 of the WLAN network 8. A call with WI is set up. If the radio wave reception intensity on the cellular interface unit CI side decreases, the call change process is executed again, and the call is changed as shown in FIG. Such call change and call disconnection processes are executed while maintaining communication between the communication terminal device 4 and the counterpart communication terminal device 5.

  In this embodiment, the process of prioritizing the WLAN interface unit WI has been described. However, as shown in FIGS. 23, 24, and 25, the cellular interface unit CI may be prioritized. FIG. 23 is a flowchart showing the processing procedure of the communication program of the communication terminal device 4, FIG. 24 is a diagram showing communication between the communication terminal devices using only the cellular switch, and FIG. 25 is an intermediary between the cellular switch, gateway and SIP server. It is a figure which shows the communication between the communication terminal devices.

  In this processing procedure, as shown in FIG. 23, at the start of communication, a power source is connected to the cellular interface unit CI to start the operation (step S81). The radio wave reception intensity is measured during communication at the cellular interface unit CI, and it is determined whether the measured value is equal to or greater than a specified value (step S82). If the measured value is equal to or greater than the specified value, the communication at the cellular interface unit CI is maintained. If the measured value is less than the specified value, the power is connected to the WLAN interface unit WI, and the radio waves on the WLAN interface unit WI side are connected. The reception intensity is measured, and it is determined whether the measured value is greater than or less than a specified value (step S83). If the measured value is less than the specified value, communication with the WLAN interface unit WI is impossible. Therefore, the power is disconnected from the WLAN interface unit WI (step S84). (Step S85), the power is disconnected from the cellular interface unit CI (step S86), and the operation is terminated.

  In step S83, if the measured value of the radio wave reception intensity of the WLAN interface unit WI is equal to or greater than the specified value, the WLAN interface unit WI can communicate, so the network side is requested to respond (step S87). A connection (call) is set in the WI, the communication is taken over from the cellular interface unit CI to the WLAN interface unit WI (step S88), and the communication is continued. After this setting, the power is disconnected from the cellular interface unit CI (step S89).

  During communication with the WLAN interface unit WI, the cellular interface unit CI is periodically connected to a power source to operate, and the radio wave reception intensity on the cellular interface unit CI side is measured. It is determined whether it exists (step S90). If the measured value is less than the specified value, the communication with the WLAN interface unit WI is maintained. If the measured value is equal to or greater than the specified value, the network side is requested to respond (step S91), a connection (call) is set in the cellular interface unit CI, and communication (from the WLAN interface unit WI to the cellular interface unit CI) is performed. To continue the communication) (step S92). After this setting, the power supply is disconnected from the WLAN interface unit WI (step S93).

  Then, in the processing sequence shown in FIG. 23, processing of the communication program in the communication terminal device 4, the network and the partner communication terminal device 5 is executed, and a call is set between the cellular interface units CI. In this case, as shown in FIG. 24, the basic call setting is performed between the cellular interface unit CI of the communication terminal apparatus 4 and the counterpart communication terminal apparatus 5 through the cellular switch 10 of the cellular network 6. The call change is performed because the radio wave reception intensity on the part CI side has decreased. In this case, as shown in FIG. 25, the cellular interface unit of the counterpart communication terminal device 5 from the WLAN interface unit WI of the communication terminal device 4 through the SIP server 14 of the WLAN network 8, the gateway 20 and the cellular switch 10 of the cellular network 6. A call with the CI is set up. When the radio wave reception intensity on the WLAN interface unit WI side decreases, the call change process is executed again, and the call is changed as shown in FIG. Such call change and call disconnection processes are executed while maintaining communication between the communication terminal device 4 and the counterpart communication terminal device 5.

[Second Embodiment]

  A second embodiment of the present invention will be described with reference to FIG. 26, FIG. 27, FIG. 28 and FIG. FIG. 26 is a diagram illustrating a configuration example of the communication terminal device 4 according to the second embodiment. FIG. 27 is a flowchart illustrating a processing procedure of the communication program of the communication terminal device 4 according to the second embodiment. 28 is a flowchart showing a call change subroutine, and FIG. 29 is a flowchart showing a call change request subroutine to the network side. It is a figure which shows the communication system with which this invention is applied. In FIG. 26, the same parts as those in FIG.

  In this embodiment, as shown in FIG. 26, the power supply line 341, the cellular baseband unit 26, and the cellular interface unit CI of the communication terminal device 4 are provided between the cellular RF front end unit 24 and the power control unit 38. A power supply line 342 is connected between the power supply control unit 38 and the cellular RF front end unit 24 and the cellular baseband unit 26 are independently supplied with power. For the WLAN interface unit WI, a power supply line 361 is connected between the WLAN-RF front end unit 30 and the power supply control unit 38, and a power supply line 362 is connected between the WLAN baseband unit 32 and the power supply control unit 38. In this configuration, the WLAN-RF front end unit 30 and the WLAN baseband unit 32 are independently fed.

  With such a configuration, the cellular RF front end unit 24 and the WLAN-RF front end unit 30 are always connected to a power source, and the cellular baseband unit 26 or the WLAN baseband unit 32 is connected to the communication state such as radio wave reception intensity. The power connection can be switched.

  Also in the second embodiment, the communication system 2 shown in FIG. 1, the communication method shown in FIGS. 2 and 3, the cellular exchange 10 shown in FIG. 7, the SIP server 14 shown in FIG. 9, and the gateway 20 shown in FIG. Is used.

  In this embodiment, communication is started by the WLAN interface unit WI. At the start of the communication, a power source is connected to the WLAN-RF front end unit 30 and then a power source is connected to the WLAN baseband unit 32. This is the same in the cellular interface unit CI.

  Therefore, in the processing procedure in the communication program of this embodiment, as shown in FIG. 27, in order to start communication with the WLAN interface unit WI, a power source is connected to the WLAN-RF front end unit 30 (step S401). A power source is connected to the baseband unit 32 (step S402), thereby enabling a communication operation and communicating by making a call (step S403).

  Here, the radio wave reception intensity with respect to the WLAN-RF front end unit 30 is measured, and it is determined whether or not the measured value is equal to or greater than a specified value (step S404). If the communication with the WLAN interface unit WI is maintained and the measured value is less than the specified value, the power is connected to the cellular RF front end unit 24 (step S405).

  Here, the radio wave reception intensity with respect to the cellular RF front end unit 24 is measured, and it is determined whether the measured value is equal to or greater than a specified value (step S406). If the measured value is less than the specified value, A disconnection process is performed (step S407). If the measured value is equal to or greater than the specified value, a power source is connected to the cellular baseband unit 26 (step S408), and the cellular interface unit CI is operated.

  In order to change the connection to the cellular interface unit CI, call change processing is executed (step S409), the power source is disconnected from the WLAN baseband unit 32 (step S410), and the power source is disconnected from the WLAN-RF front end unit 30 ( Step S411).

  Here, the radio wave reception intensity for the cellular RF front end unit 24 is measured, and it is confirmed whether the measured value is equal to or greater than a specified value (step S412). If the measured value is equal to or greater than the specified value, If the communication at the cellular interface unit CI is maintained and the measured value is less than the specified value, the power source is connected to the WLAN-RF front end unit 30 (step S413).

  The radio wave reception intensity with respect to the WLAN-RF front-end unit 30 is measured, and it is confirmed whether or not the measured value is greater than or less than a specified value (step S414). (Step S415), and if the measured value is equal to or greater than the specified value, a power source is connected to the WLAN baseband unit 32 (step S416).

  In order to change to the connection of the WLAN interface unit WI, the network side is requested to change the call (detour setting) (step S417), the power is disconnected from the cellular baseband unit 26 (step S418), and the cellular RF front end unit 24 The power is turned off (step S419), and the process proceeds to step S404.

  Next, a subroutine for call change processing (step S409) will be described with reference to FIG.

  In the call change process (step S409), the cellular interface unit CI requests the cellular exchange 10 to set up a call between the cellular exchange 10 and the gateway 20 (step S421). That is, when communication is performed using the WLAN interface unit WI, the communication terminal device 4 is a process of establishing a call by the cellular interface unit CI when the radio wave reception intensity of the WLAN interface unit WI decreases. Therefore, the communication terminal device 4 requests the cellular exchange 10 to set the route (call) of the communication terminal device 4 -the cellular exchange 10 -the gateway 20. In this case, the cellular exchange 10 performs the same processing as the normal call setting, and the gateway 20 is positioned as if it is the counterpart communication terminal apparatus 5 from the communication terminal apparatus 4, and the telephone number of the gateway 20 is designated to the cellular exchange 10. Request a connection. The cellular exchange 10 does not distinguish from normal call setting, and no instruction from the communication terminal device 4 to the gateway 20 is particularly necessary. Based on this request, a notification of completion of call setting is received from the cellular switch 10 (step S422).

  The WLAN interface unit WI requests the SIP server 14 to change the call (step S423). In this case, the route (call) between the cellular exchange 10 and the gateway 20 is established, but the route between the gateway 20 and the WLAN interface unit WI of the counterpart communication terminal device 5 is not yet established. Therefore, in order to set a route (call) from the gateway 20 to the WLAN interface unit WI of the counterpart communication terminal device 5, a request is made to the SIP server 14 that performs network control. At this time, if the partner communication terminal device 5 has already made a call using the WLAN interface unit WI, the call (call) is changed to the route of the gateway 20, so that “change request” or “change request” of call change is made. Is required.

  Based on this request, the SIP server 14 receives a notification of call change approval (step S424). Thereby, a call connection completion notification is received from the partner communication terminal device 5 (step S425), and the process returns to step S410 (FIG. 27).

  Next, a subroutine for a call change request to the network side (step S417) will be described with reference to FIG.

  In this call change request (step S417), the WLAN interface unit WI requests the SIP server 14 to change the call, that is, a new call (call C) (step S431). A notification of acceptance of change acceptance is received from the SIP server 14 (step S432).

  The cellular interface unit CI requests the cellular exchange 10 to disconnect the call B (step S433). Based on this, the SIP server 14 receives a disconnection notice from the cellular exchange 10 (step S434). As a result, a call with the counterpart communication terminal device 5 via the WLAN network 8 is started (step S435), and the process returns to step S418 (FIG. 27).

[Third Embodiment]

  A third embodiment of the present invention will be described with reference to FIG. FIG. 30 is a flowchart showing a processing procedure of the communication terminal apparatus 4 according to the third embodiment.

  The communication terminal device 4 of this embodiment is the same as that of the second embodiment (FIG. 26), and the cellular RF front end unit 24 and the WLAN-RF front end unit 30 are always connected to a power source, and the radio wave reception intensity. The connection of the power source to the cellular baseband unit 26 or the WLAN baseband unit 32 can be switched according to the communication state.

  Also in the third embodiment, the communication system 2 shown in FIG. 1, the communication method shown in FIGS. 2 and 3, the cellular exchange 10 shown in FIG. 7, the SIP server 14 shown in FIG. 9, and the gateway 20 shown in FIG. Is used.

  Therefore, a power source is connected to the WLAN-RF front end unit 30 (step S501), a power source is connected to the WLAN baseband unit 32 (step S502), and communication is performed by a call (step S503).

  Here, the radio wave reception intensity with respect to the WLAN-RF front end unit 30 is measured, and it is determined whether the measured value is equal to or greater than a specified value (step S504). If communication with the unit WI is maintained and the value is less than the specified value, a power source is connected to the cellular RF front end unit 24 (step S505).

  Here, the radio wave reception intensity with respect to the cellular RF front end unit 24 is measured, and it is determined whether the measured value is equal to or greater than a specified value (step S506). If the measured value is less than the specified value, A disconnection process is performed (step S507), and if the measured value is equal to or greater than a specified value, a power source is connected to the cellular baseband unit 26 (step S508).

  In order to change the connection to the cellular interface unit CI, a call change process (subroutine shown in FIG. 28) is executed (step S509), the power is disconnected from the WLAN baseband unit 32 (step S510), and the WLAN-RF front end unit The power supply is disconnected from 30 (step S511).

  Here, the radio wave reception intensity with respect to the cellular RF front end unit 24 is measured, and it is determined whether or not the measured value is equal to or greater than a specified value (step S512). If the measured value is less than the specified value, A power source is connected to the WLAN-RF front end unit 30 (step S513). Moreover, the radio wave reception intensity with respect to the WLAN-RF front end unit 30 is measured, and it is determined whether the measured value is equal to or greater than a specified value (step S514). If the measured value is less than the specified value, A cutting process is performed (step S515).

  In step S512, if the measured value is equal to or greater than the specified value, whether or not the specified time has elapsed as a unit time for maintaining the communication at the cellular interface unit CI and checking the state of the WLAN interface unit WI. Is confirmed (step S516). If the specified time has not elapsed, the system waits until the specified time elapses (step S512). If the specified time has elapsed, the WLAN-RF front end unit 30 is powered on. Connect (step S517), measure the radio wave reception intensity for the WLAN-RF front end unit 30, and if the measured value is less than the specified value, return to step S512, and if the measured value is equal to or greater than the specified value, The process proceeds to step S519.

  If the measured value of the radio wave reception intensity at the WLAN-RF front end unit 30 is equal to or greater than the specified value, a power source is connected to the WLAN baseband unit 32 (step S519), and the connection is changed to the WLAN interface unit WI. The network side is requested to change the call (bypass setting) (step S520), the power is disconnected from the cellular baseband unit 26 (step S521), the power is disconnected from the cellular RF front end unit 24 (step S522), and the step The process returns to S504.

  Through such processing, the priority of the WLAN interface unit WI is secured, the connection is changed according to the radio wave condition, and communication is maintained.

[Other Embodiments]

  (1) In the above embodiment, the communication terminal device 4 is exemplified as the communication device. However, any communication device that includes the cellular interface unit CI and the WLAN interface unit WI and enables communication with a plurality of communication networks. The present invention can be applied, for example, as shown in FIG. 31, a communication system including personal computers (PCs) 604, 605 and the like having a cellular interface unit CI and a WLAN interface unit WI and having a communication function. In addition, as shown in FIG. 32, a communication system 2 including personal digital assistants (PDAs) 704 and 705 having similar functions may be configured.

  (2) In the above embodiment, the communication terminal device 4, the PCs 604, 605, the PDAs 704, 705, etc. having the cellular interface unit CI and the WLAN interface unit WI are exemplified as the communication devices. In addition to a so-called dual terminal, another communication network, for example, an interface unit corresponding to WiMAX or the like, may be configured to perform power source switching of three or more interface units.

  Next, technical ideas extracted from the embodiments of the present invention described above are listed as appendices according to the description format of the claims. The technical idea according to the present invention can be grasped by various levels and variations from a superordinate concept to a subordinate concept, and the present invention is not limited to the following supplementary notes.

(Appendix 1) A communication device that is wirelessly connected to a plurality of networks and performs communication through each network,
A plurality of interface units corresponding to the network;
Depending on the communication status of the communicating interface unit, connect one of these interface units to the power source, connect the inactive interface unit to the power source, and other interfaces that were inactive from the communicating interface unit A control unit that switches communication to the unit,
And switching the interface unit while maintaining communication with the communication destination.

(Appendix 2) In the communication device of Appendix 1,
A communication apparatus comprising: a communication control unit configured to transmit information indicating communication switching to the interface unit when switching the communication from the interface unit in communication to the interface unit that has been dormant.

(Appendix 3) In the communication device of Appendix 1,
A power source for connecting a plurality of interface units corresponding to the network;
A connection switching unit for switching the connection between the interface unit and the power source;
A communication apparatus comprising:

(Appendix 4) In the communication device of Appendix 1,
The interface unit includes a signal processing unit that processes a signal to be transmitted or received, and a wireless communication unit that transmits the signal by a radio signal or receives a radio signal,
A communication apparatus comprising: connecting the power source to the wireless communication unit to confirm a radio wave reception state; and connecting the power source to the signal processing unit according to the radio wave reception state.

(Additional remark 5) It is the server apparatus which is installed in the network side connected with a communication apparatus, and communicates with the said communication apparatus,
A receiving unit that receives a call change request accompanying switching of the interface unit from a communication device including a plurality of interface units;
When the receiving unit receives call change request information, a notification unit that notifies the other network side of the request information;
A server device comprising:

(Additional remark 6) It is a relay apparatus connected to the some network connected with a communication apparatus, and relaying between each network,
Receiving a call change request information from the network in communication with the communication device, comprising a control unit for changing the call;
A relay device that changes a call to a network corresponding to an interface unit of the communication device.

(Supplementary Note 7) A communication system including a plurality of networks and a communication device that includes a plurality of interface units and is wirelessly connected to the network to perform communication,
A communication system comprising a switching processing unit that receives switching information of communication with the network accompanying switching of an interface unit from the communication device and switches a network that performs communication with the interface unit of the communication device.

(Supplementary note 8) A communication method for wirelessly connecting to a plurality of networks and performing communication through each network,
Connecting a power source to one of the interface units to operate,
Monitoring the communication state of the communicating interface unit;
A step of operating the inactive interface unit connected to a power source according to the communication state;
And switching the communication from the communicating interface unit to another interface unit, and switching the interface unit while maintaining communication with the communication destination.

(Supplementary note 9) In the communication method of supplementary note 8,
A communication method comprising the step of transmitting communication switching information from the interface unit when switching communication from the interface unit in communication to the interface unit that has been dormant.

(Additional remark 10) It is a communication program which makes a computer execute and communicates,
Executing a process of connecting a power source to any of the interface units;
Monitoring the communication state of the communicating interface unit and determining the deterioration of the communication state;
Executing a process of connecting a power source to an inactive interface unit according to a communication state;
Executing a process of switching communication from the communicating interface unit to another interface unit;
Including a communication program.

(Appendix 11) In the communication program of Appendix 10,
Executing a process of switching communication from the interface unit that is in communication to the interface unit that has been suspended; and
Executing the process of transmitting communication switching information from the interface unit when switching the communication;
Including a communication program.

(Supplementary note 12) A recording medium storing a communication program for causing a computer to execute communication,
Executing a process of connecting a power source to any of the interface units;
Monitoring the communication state of the communicating interface unit and determining the deterioration of the communication state;
Executing a process of connecting a power source to an inactive interface unit according to a communication state;
Executing a process of switching communication from the communicating interface unit to another interface unit;
And a computer-readable recording medium storing a communication program, wherein the communication program is stored in a computer program.

(Supplementary note 13) In the recording medium of Supplementary note 12,
Executing a process of switching communication from the interface unit that is in communication to the interface unit that has been suspended; and
Executing the process of transmitting communication switching information from the interface unit when switching the communication;
And a computer-readable recording medium storing a communication program, wherein the communication program is stored in a computer program.

As described above, the most preferable embodiment and the like of the present invention have been described. However, the present invention is not limited to the above description, and is described in the claims or disclosed in the specification. It goes without saying that various modifications and changes can be made by those skilled in the art based on the above gist, and such modifications and changes are included in the scope of the present invention.

The present invention selects a plurality of interface units and saves power by switching the connection of the power supply to the interface unit, while maintaining communication in response to a deterioration in communication state such as a change in radio wave reception intensity, The interface unit can be switched and a call can be changed, and communication reliability can be maintained, which is useful.

It is a figure which shows the communication system which concerns on 1st Embodiment. It is a flowchart which shows the process sequence by the side of a communication terminal device. It is a flowchart which shows the process sequence by the side of a network. It is a figure which shows an example of a communication terminal device. It is a figure which shows the structural example of a program data storage memory. It is a figure which shows an example of a communication terminal device. It is a figure which shows an example of a cellular switchboard. It is a figure which shows the structural example of a program data storage memory. It is a figure which shows an example of a SIP server. It is a figure which shows the structural example of a program data storage memory. It is a figure which shows an example of a gateway. It is a figure which shows the structural example of a program data storage memory. It is a flowchart which shows the process sequence of the communication program of a communication terminal device. It is a flowchart which shows the processing procedure of the communication program of a SIP server. It is a flowchart which shows the process sequence of the communication program of a gateway. It is a flowchart which shows the process sequence of the communication program of a cellular switch. It is a sequence diagram which shows the process sequence of the communication program in a communication terminal device, a network, and a partner communication terminal device. It is a sequence diagram which shows the process sequence of the communication program in a communication terminal device, a network, and a partner communication terminal device. It is a sequence diagram which shows the process sequence of the communication program in a communication terminal device, a network, and a partner communication terminal device. It is a sequence diagram which shows the process sequence of the communication program in a communication terminal device, a network, and a partner communication terminal device. It is a figure which shows the communication between the communication terminal devices only by a SIP server. It is a figure which shows the communication between the communication terminal devices which intervened the SIP server, the gateway, and the cellular switchboard. It is a flowchart which shows the process sequence of the communication program of a communication terminal device. It is a figure which shows the communication between the communication terminal devices only by a cellular switchboard. It is a figure which shows the communication between the communication terminal devices which intervened the cellular switchboard, the gateway, and the SIP server. It is a figure which shows the structural example of the communication terminal device which concerns on 2nd Embodiment. It is a flowchart which shows the process sequence of the communication terminal device which concerns on 2nd Embodiment. It is a flowchart which shows the subroutine of a call change. It is a flowchart which shows the subroutine of the process of the request | requirement of the call change to the network side. It is a flowchart which shows the process sequence of the communication terminal device which concerns on 3rd Embodiment. It is a figure which shows the communication system which concerns on other embodiment. It is a figure which shows the communication system which concerns on other embodiment.

Explanation of symbols

2 communication system 4 communication terminal device 5 partner communication terminal device 6 cellular network 8 WLAN network 10 cellular switch 14 SIP server CI cellular interface unit WI WLAN interface unit 20 gateway 24 cellular RF front end unit 26 cellular baseband unit 30 WLAN-RF front End part 32 WLAN baseband part 38 Power supply control part 40 Battery 42 CPU

Claims (5)

A communication device that is wirelessly connected to a plurality of networks and performs communication through each network,
A plurality of interface units corresponding to the network;
Depending on the communication status of the communicating interface unit, connect one of these interface units to the power source, connect the inactive interface unit to the power source, and other interfaces that were inactive from the communicating interface unit A control unit that switches communication to the unit,
And switching the interface unit while maintaining communication with the communication destination. A relay device connected to a plurality of networks connected to a communication device and relaying between each network,
Receiving a call change request information from the network in communication with the communication device, comprising a control unit for changing the call;
A relay device that changes a call to a network corresponding to an interface unit of the communication device. A communication system including a plurality of networks and a communication device that includes a plurality of interface units and communicates wirelessly with the network,
A communication system comprising a switching processing unit that receives switching information of communication with the network accompanying switching of an interface unit from the communication device and switches a network that performs communication with the interface unit of the communication device. A communication method wirelessly connected to a plurality of networks and performing communication through each network,
Connecting a power source to one of the interface units to operate,
Monitoring the communication state of the communicating interface unit;
A step of operating the inactive interface unit connected to a power source according to the communication state;
And switching the communication from the communicating interface unit to another interface unit, and switching the interface unit while maintaining communication with the communication destination. A communication program for performing communication with a computer,
Executing a process of connecting a power source to any of the interface units;
Monitoring the communication state of the communicating interface unit and determining the deterioration of the communication state;
Executing a process of connecting a power source to an inactive interface unit according to a communication state;
Executing a process of switching communication from the communicating interface unit to another interface unit;
Including a communication program.

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